21324115 has 4 divisors (see below), whose sum is σ = 25588944. Its totient is φ = 17059288.

The previous prime is 21324113. The next prime is 21324119. The reversal of 21324115 is 51142312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21324115 - 2¹ = 21324113 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21324092 and 21324101.

It is not an unprimeable number, because it can be changed into a prime (21324113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2132407 + ... + 2132416.

It is an arithmetic number, because the mean of its divisors is an integer number (6397236).

Almost surely, 2^21324115 is an apocalyptic number.

21324115 is a deficient number, since it is larger than the sum of its proper divisors (4264829).

21324115 is an equidigital number, since it uses as much as digits as its factorization.

21324115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4264828.

The product of its digits is 240, while the sum is 19.

The square root of 21324115 is about 4617.8041318358. The cubic root of 21324115 is about 277.3045562640.

Adding to 21324115 its reverse (51142312), we get a palindrome (72466427).

The spelling of 21324115 in words is "twenty-one million, three hundred twenty-four thousand, one hundred fifteen".